1. Field
The present disclosure relates to equipment that can be maneuvered manually, for example concrete saws having a portion that may be lifted or raised, relative to a surface, using handles or other manual elements at another portion of saw. Such saws may include industrial concrete saws for cutting and grooving concrete slabs.
2. Related Art
In the concrete industry, large slabs of concrete are used to form road beds, building floors and other structures used for its strength and durability. Seams, grooves or other cuts in the concrete may be made in the slabs to form expansion joints, control stress cracks as the slabs cure or to form channels or openings in the slabs to accept other structures. Concrete saws are used to cut the seams, grooves or other openings, and such concrete saws are often very heavy and difficult to move along the concrete slab.
For large or heavy construction applications, heavy self-propelled saws or other large concrete saws are used. Examples of concrete saws and their construction and operation can be found in a number of patents, including U.S. Pat. No. 5,809,985, entitled “Self-Propelled Saw,” U.S. Pat. No. 5,743,247, entitled “Method and Apparatus for Safe Operation of Self-Propelled Concrete Saw,” U.S. Pat. No. 5,680,854, entitled “Self-Propelled Saw,” U.S. Pat. No. 5,477,844, entitled “Slurry Recovery System for a Wet Cutting Saw,” and U.S. Pat. No. 4,664,645 entitled “Blade Drive Shaft Assembly,” all of which are incorporated herein by reference. During setup and operation of the saw, an operator walks behind the saw to control the direction, cutting speed, cutting depth and other operating conditions under which the saw operates. The saw includes one or more wheels allowing the saw to move along the concrete and a frame supported by the wheels on which is mounted a motor or other power supply for operating a saw blade and often for driving one or more wheels to move the saw along the concrete surface. One or more handles extend behind the saw about the level of an operator's hands to allow the operator to manually position the saw. Typically, the saw blade is in the front of the saw and handles extend behind the saw.
For a typical straight cut, the operator aligns the saw blade and often a cutting guide with the intended cutting path. The saw is maneuvered with the saw blade raised above the concrete until the blade and cutting guide are aligned with the cutting path. With the saw blade raised, the orientation of the entire saw is pivoted typically about an axis common to rear drive wheels, and the handles are thereby lowered a corresponding amount. See for example FIG. 1 in the U.S. Pat. No. 5,477,844 patent. The entire saw may tilt as much as 30 degrees, pivoting on the rear wheels near the operator. The operator guides the saw travel by lifting and pushing or pulling on handle bars. With the handles lowered, the operator may be stooped over in an uncomfortable position while at the same time trying to maneuver the heavy saw. Maneuvering the saw may often include turning or moving the saw to one side or the other while pushing down or pulling up on the handles or to make easier the positioning of the saw blade. Consequently, the operator's hands change position with the handles often resulting in the operator being stooped over while moving the heavy saw.
Saw handle bars can be repositioned by removing the handle bar from the saw and re-inserting it in a different position that better accommodates the operator's preferences. A handle bar lock mechanism is released to remove the handle bars and tightened after they are repositioned. However, the alternate handle bar position may not be suitable for other operators, depending on the preferences of the operators.